In Japanese there’s 地球 which means Earth (this planet), and 土 which means soil.

地 can also mean soil, but it’s a different word from 地球 meaning the planet earth. I don’t think it’s commonly used by itself to mean soil either, but I could be wrong.

It means ground, as in the surface on which we live and build things on. 球 means ball or sphere. I wonder if that’s the reason why flat Earthers are rare in China and Japan - the very phrase ‘flat Earth’ is an oxymoron in these languages :)

Right, but the word 地球 can only mean the planet Earth, it’s not synonymous with anything else and there’s no room for confusion.

Soil, or ground (on any planet) is a different word. There’s not much room for confusion.

I was under the impression that 土 could be used for "earth," so I apologize. Thanks for the correction!

I’ve not heard it used that way, but I could be wrong. There’s possibly also a historical usage in this sense.

In Kim Stanley Robinson’s Mars trilogy, they study areology.